There are two types of headache after taking cephalosporin: one is a common side effect of the drug after taking cephalosporin, the patient will have headache, nausea and even vomiting; the other is an allergic reaction after taking cephalosporin, in addition to gastrointestinal reactions such as headache, nausea and vomiting, it may be accompanied by a rash all over the body, as well as puffiness of the eyelids, lips and face. If you have a headache, dizziness, or nausea after taking this drug, you should first observe whether there is a rash on your body, and then look at your face, eyes, lips, and mouth for edema, and whether you have difficulty breathing. If there is a combination of these emergencies, it may be a drug allergy, you can take oral anti-allergy drugs at home, such as loratadine, paracetamol, cetirizine, etc., and then immediately call an emergency vehicle, and the doctor will give simple treatment and then send to the hospital. If it is just dizziness, headache, nausea, gastrointestinal discomfort, it may be a side effect of the drug. In the future, pay attention not to take cephalosporin antibiotics on an empty stomach, but try to take them half an hour after meals. In addition, patients with penicillin and cephalosporin allergies should be careful not to take cephalosporin antibiotics orally on their own.